Aviation trainer



May 31, mm

E: A. LENK, JR

AVIATION TRAINER Filed July 26,1 1934 2 Sheets Shetl mmwzea.

ATTORNEY.

F BE, 1938;

E. A; LINK, JR

AVIATION TRAINER 2 Sheets-Sheet 2 Filed July 26, 1934 INVENTOR. EDWIN A. All/k. dz.

ATTORNEY Patented May 31 1938 v I 2,119,083 AVIATION TRAINER.

Edwin A. Link, Jiu, Cortland, N. Y.

Application July 26, 1934, Serial No. 737,081 4 Claims. (Cl. 3542) My invention relates to. an aviation trainer an airport is located a specified distance from the and particularly to a means of training pilots in landing field, say two miles, and so arranged that the art of blind or radio flying and air navigathe landing field is directly on one of the ontion. course line of signals from the station.

5 With the development of aviation and the esy this y t of radic Signaling from t e 5 tablishment of scheduled operations on definite vari irp pilots are able to fly directly courses between fixed points, there has been into their destination solely .by instruments and cluded the directional radio beam comprising without the necessity of sight 't e ground. radio broadcasting stations located at the air- It will be obvious that in order for a pilot to ports which comprise the terminals of various become skilled in the art of this blind or radio 10 These radio broadcasting stations send flyi it requires considerable rai and pra out, directionally, signals receivable by the radio tice. It is also equally bv s t at f a pilot to receiving sets in the aeroplanes and rendered iv the necessary training and P e y audible and/0r visible to the pilot through suitaa t a fl t a d tru t n in n a r plan th ble translation means such as earphones, pointer 00st thereof is necessarily high- 1., indicators, and the like. In some instances such It is e p c p ob t of y invention, theresignals are translated into both audible and visual fcrc, to provide a means of training and instructindications fo the pilot ing pilots in this art of blind or radio flying and The nature of these signals broadcast .from the to make it possible for them to Practice d various stations is such as to inform the pilot as ccmc thoroughly familial W this yp of flying '20 to his position with. respect to a direct line course in a trainer 0n the d, a ng t e e to the particular station from which the signals Dense of actual flight training P t e a d n I are sent, The dibl ignals a h t t if addition eliminating the hazard of strident blind the pilot is to the right of a certain course to a fi 3 given airport-and station, a code signal representone Of the important features a Objects f 5 ing the letter N and constituting a dash-dot sigmy invention s in t prov io of a trainer nal will be heard. If the student is to the left c ab of directional control a d p ef ably simof the course he will hear the code signal repreulathig as nearly as P b t e actual eel and senting the letter A, namely, dot-dash. If the control of an aeroplane Within W ch the 3:) student is directly on-course, his signal will con-- student Pilot m be enclosed 80 th his V slc stitute a continuous hum without distinction bes limited el to the st u ts in t traintween dots and dashes. er corresponding exactly to the instruments in The volume of these signals will increase-as the an aeroplane, a d u d par ularly am pilot approaches the airport and sending stamany which might p a compass The on and n decrease if i flight is away from pilot is also provided with a loud speaker or a set such station. of earphones by which audible signals corre- The signals sent out by the stations also inspchdihg to se above described in actual D clude periodically the code signal of the station tic'e, can be heard, if e d, w h a v al and airport from which the signals are being indicator responsive to the signals for visually broadcast. For instance, three dots might be the t s g e signals. 40

station signal of a given airport. A s na tr s tt ppa atus is pr v ded If the receiving set in the aeroplane is equipped under the control of an instructor by' means of with a visual indicator of known type, the pointer which the signals are communicated to the stuor other indicating member will respond in like dent in the trainer. The instructor by constantly i 5 manner to show whether the plane is to the right checking the position ofthe trainer on its supor left or on a given course. port, under the control of the student therein, is

These broadc in stations are so i n able with the signal transmitting service, to comand shielded that when a pilot is directly over a municate to the student within the trainer the station no signals will be heard. Consequently signals corresponding exactly to the actual no a pilot flying into a station and receiving the sigbroadcast signals above described, and to observe nals continuously as above described, knows imand to record on a suitable chart the "progress" mediately when he is passing directly over the or the student in response to such signals. sending station, because of the complete inter- By this. method of instruction a pilot may be ruption of the receiving of the signals. taught to fly by radio and may acquire a very UNITED STATES PATENT OFFICE :3 In actual practice the broadcasting station for definite degree of efliciency therein before going in the trainer and to either the expense or the hazard of actual flight. V

One feature and obiect of my invention lies in the provision of a novel signaling device by Other objects and advantages will be apparent.

as the description proceeds, reference now being had to the figures of the accompanying drawings forming a part of this application and wherein like reference numerals indicate like parts. It is to be understood that the form of apparatus herein shown and described is but illustrative only as it will be apparent that the apparatus used may vary greatly in detail without departing from the invention. In the drawings: Figure 1 is a diagrammatic iilustraiilonoi the complete apparatus used, in assembled relation. Figure 2 is a detail view of a form of chart by means of which the test flights" of the student may be recorded.

Figure 3 is a diagrammatic view. the electrical signal providing means.

Figure 4 is a detail view illustrating a portion of the automatic signal providing mechanism.

illustrating The reference character I refers generally to a trainer of a type suitable for use with this invention and resembling generally that shown and described in applicant's prior Patent No. 1,825,462 issued September 29,1931. The details of this trainer have not been shown nor will they be described herein as they form no part of this invention except in the combination as hereinafter claimed. Suflice it to say that the trainer constitutes essentially a frame simulating the construction of an aeroplane and provided with a cockplt seat 2 in which the student pilot is positioned. A hood 3 isprovided to completely enclose a student within the cockpit so as to limit his vision to the instruments therein, such as the compass 4 and, if desired, a visual radio indicator 4a.

The trainer is suitably supported upon a rotatable member 5 which may be provided with any desired or suitable means for rotation with the trainer upon a base or support 6. It will be understood, of course, that the rotation of the trainer is under the direct control of the student that it is suitably adapted for complete 360 degree rotation upon the support 8. In other words, the student within the trainer is able by any desired or suitable means (not shown) to rotate the trainer to any position of the compass desired. The rotatable support 5 is suitably marked'or graduated as at I, such structor or operator in order that he may observe with accuracy the exact directional position of the trainer at all times. This is for a purpose to be described.

It should be understood clearly that the particular type of trainer is relatively unimportant. Many forms of apparatus may be used. It is applicants intention that the word trainer.' as hereinafter used shall include any desired, construction of non-flying type, that is, incapable of actual flight but controllable as to directional position.

The signal sending apparatus is indicated generally at 9 and may be suitably supported upon a table ill or the like, the electric signal impulses being transmitted to the trainer bysuitable wires H. The arrangement of the signaling device and the trainer is such that the instructor or operator has at all times a clear view of the trainer while operating the signaling device.

It will be understood that in order to provide proper instruction and training to the student pilot, signals must be provided for him which simulate in closest detail the actual broadcast signals of a radio station to aeroplanes in flight. My signaling means for this purpose will now be described.

With reference to Figure 4 it will be observed that I have provided a motor i2, the shaft I 3 of which is provided with a gear l4 meshing with a gear IS on a shaft it. Mounted upon this shaft l6 for rotation therewith is a contact wheel I! provided at spaced points on its periphery with fixed contacts l8 and IS, the former being relatively longer than the latter so as to provide, in a manner hereinafter described, distinguishable "dash and dot signal impulses. It will be noted from Figure 3 that these contacts l8 and I9 are spaced apart and it should also be understood at this point that the number of such contacts and the size of the wheel ll, as well as the speed thereof, are all subject to variation without departing from the invention. A brush contact member 20 is provided for cooperation periodically and successfully with the contacts l8 and I9 as the wheel I! rotates. The periodic engagement of the contact 20 and the contacts i8 and i9 serves to close an electric circuit, the source of energy of which isprovided by a battery 2| and which circuit is indicated by the wires 22. Included in this circuit is an electromagnet 23 which obviously is periodically energized by the engagement of the contacts 18 and IS with the contact 20, the periods of energization corresponding with the size of the contacts i 8 and i9 and the'time they are engaged with the contact 20. Obviously the magnet 23 will thus be energized for successive relatively long and short periods corresponding to dashes and dots respectively.

The armature for the electromagnet 23 comprises a pivoted arm 24 pivoted at 25 and normally held out of engagement with the magnet 23 by a coil spring 26. Carried at one endof the arm 24 is a pair of spaced spring contact arms 21 and 28 carrying the contacts 29 and 38 respectively. IHxedfin cooperative relation with these contacts 29 and 30 are the stationary conncts 3| and 32 respectively. In the normal position, that is, with the magnet 23 not energized and the spring 26 holding the armature arm 24 upwardly. the contact 29 is in engagement with the contact 3|. When the magnet 23 is energized, the contact 30 moves into engagement with the contact 32. The spring material of the contact arms 21 and 28 is such that during the movement of the armature 24 downwardly, the contact 2! remains in engagement with the contact 3| until after the contact 30 has engaged the contact 32. When the armature 24 is in its lowermost position in engagement with the magnet 23, the contact 29 disengages the contact 3|, and remains disen gaged until the circuit to the magnet 23 is broken and the armature 24 again moves upwardly under the influence of spring 26. During suchirej turn movement, the contact 36 remains in engagementwith the contact 32 until the contact 29 engages thecontact 3|.- In the uppermost position, the contact 36' leaves the contact .32. This arrangement is for a purpose which will appear from the description to follow.

Referring to Figure 3 it will be noted that there is'provided a hummer circuit consisting of the wires 33 and includinga primarycoil 34 and a common microphone'hummer 34a, well known in the art. This hummer device may be of the order of a thousand cycles and receives its energy from the same battery source 2|. The

hummer'circuit serves to modulate the battery circuit with corresponding impulses delivered through the primary coil 34. A secondary coil 35, cooperating with the primary 34 includes in its circuitthe contacts 29 and and, through the contacts 3| and 32, a pair of primary coils 36 and 31. Obviously therefore, the-signals from the primary 34 of the hummer circuit, induced into the secondary 35,'are transmitted to either the primary 36 or the primary 31, depending upon whether the contact 29 engages the contact 3| or whether the contact 36 engages the contact 32. It will also be apparent thatdue to the arrangement of the contacts l6 and IS on the wheel l1, and the energization of the magnet 23 by the actuation of such contacts with the brush -20, the induced hummer signals or impulses in the primary 36 will be in the nature of dash-dot signals and those in the primary 31 will be in the nature of dot-dash signals. This is obvious from the fact that when the magnet 23 is energized in a, dash-dot sequence, such sequence being carried out by the corresponding engagement of the contact 30 and contact 32, the opposite sequence will prevail as between the contact 29 and contact 3|.

The primaries 36 and 31 are the same size and length and are spaced apart a distance of substantially the length of one 01' them. A secondary coil 38 is provided for cooperation with both of the primaries 36 and 31 and is suitably arranged for adjustment with respect to the primaries 36 and 31 whereby it may be moved to a position adjacent the coil 31 and in such position will induce the signals therefrom. If adjusted to a position adjacent the primary 36 it will induce the signals from such primary. If it is adjusted to a position intermediate the two primaries 36 and 31 it will induce enough of the signals from both primaries to result in a continuous hum signal, the dot-dash of one primary and the dashdot of the other primary succeeding each other in a manner to provide a continuous unbroken hum signal in the secondary 38. By the same token the intermediate positions of adjustment of the secondary 38 toward either of the primaries 36 or 31 will result in an induced signal of the primary nearest which the secondary is located, predominating.

The induced current from the secondary 36 is amplified by a suitable amplifier 39 of any desired construction or arrangement and the output of such amplifier is carried by the wires II to the earphones 4| and/or the visual indicator 4a throughsuch other translating devices or receiv'ers necessary to render the signals-audible and/or visible to the student in t e trainer- In' order that the signals may be periodically interrupted and a station signal given in simulation of actual conditions as previously explained, the shaft 16 is provided with a second wheel 42 1 having on its periphery a series of spaced con tact members 43 corresponding to the desired station signal to be given, 'for instance, three dots". Obviously, any particular combination of dots" and dashes can be provided but the three dots illustrate the'feature' here described. Cooperating with the contacts '43 is a brush contact member 44 in position to periodically engage the contacts 43 as the wheel 42 is rotated. The contacts 43 and 44 are included in thecircuit of the secondary 35 of the hummer device and as the wheel 42 rotates continuously, the normal operation would be for such contacts to continuously modulate the hummer circuit so that the signals provided by the cooperation of these contacts would be heard continuously in the earphones. A short circuit is provided for the circuit of these contacts 43 and 44, however. comprising the wires 45 and a contact wheel 46 mounted upon a shaft 41 upon which is also a gear 48 meshing with a gear 49 on the motor shaft l3 whereby the contact disk 46 is continuously rotated from the mo-. tor. A brush contact member 56 is provided for engaging the periphery of the contact disk 46 and when such contact engagement is established, as is normally the case, the circuit of the contacts 43 and 44 is sh0rted", thereby ofisetting and eliminating the influence of the signals produced by the contacts 43 and 44 upon the circuit of the secondary 35. The disk 46 isprovided on its periphery, however, with a notch 5| whichperiodically reaches the brush contact 56, thus breaking the short circuit and permitting the signals produced by the contacts 43 and 44 to modulate the induced current in the secondary 35 and consequently respond in the primaries 36 and 31 and in the secondary 38 to the earphones 4|.

The operation of the contact disk 46 with its brush contact 50 is so arranged and timed that during the period when the contact 50 is in the slot 5| and out of contact with the disk 46, the three dot signals will be repeated twice. The causing of these three dot signals is also arranged and timed with respect to the contact disk or wheel |1 that one set of three "dot signals willbe induced through the primary 36 and the next sent through the primary 31. This is also in simulation of the actual broadcasting of corresponding signals to planes in actual flight wherein the station call or signal is periodically given twice, once on each side of the true course.

A suitable volume control 52 is provided on the amplifier 39 whereby the volume of the signals transmitted to the earphones 4| can be varied. A volume control 52a is also provided in the trainer by means of which the student can adjust the volume of signals received.

I have also provided means whereby the in structor can talk to the student pilot in the trainer during his test flight. This means comprises a microphone 52b, the circuit of which may receive its energy from a battery 52c, or if desired, from the battery 2|. The microphone circuit includes a, transformer 52d and is located for cutting into the input of the amplifier circuit by means of a double pole, double throw switch 52e. By this means the instructor may at any time interrupt the test flight andtalk to the student pilot in the trainer, to advise or instruct him. It has been found useful as a matter of training, for the instructor to periodically interrupt the sig-- nals and give the student weather reports by this means,'corresponding to actual broadcast renow be described. The student pilot having been instructedas to the meaning of the various signals above explained, is placed in the trainer and the hood 3 drawn over him so that he must control the direction of his test "flight" solely by the compass 4 and the signals, visual. or audible, which he receives from the signal sending device. The instructor may, of course, assume any desired position for the trainer, representing a plane in flight, with respect to a radio station and airport and will then proceed to give the signals to the student in the trainer which correspond to the initial assumed position of the trainer, and through its various turns corresponding to the same signalswhich an actual plane in flight in a corresponding initial position and corresponding turns and paths, would receive from an actual radio station. The instructor also assumes the pilot and trainer to be a given distance from the airport and station and assumes a constant speed of flight. With-these factors, and by checking the time element of the test "flight and by watching the graduations I on the trainer with respect to the fixed pointer, the instructor is able to observe and to chart the course of the student pilot responsive to the signals given him by the instructor.

In Figure 2 is illustrated a typical chart which may be used for this purpose although it will be understood that the particular details thereof may be varied considerably without departing from the invention. This chart comprises a disk 53 provided with concentric circle lines 54 drawn around a centrally located broadcasting station 55. On this chart are also drawn the so-called on course radio, beams represented by the lines 56 and 56a. I

This chart corresponds to a typical radio beam map for a given station and airport which sends out beams in four directions, in the instance shown, 60 east of north, 30 south of east, 60 west of south, and 30 north of west. Such maps are available to the public and the student pilot in the trainer is preferably, though not necessarily, provided with one to assist him in his instruction and training. In the illustration here given it will be assumed that the student pilot in the trainer is supplied with a map showing the corresponding beams and station as is shown on the chart 53, or at least is familiar with it and knows that this test flight is to be to the station and airport thereof. These maps also show which beam" and which direction from the station, the landing field is located.

0n the chart, the landing field or airport A is located on the beam or course extending 60 east of north from the station.

It'will benoted that the beams" as shown on the chart divide the area around the station and airport into four quadrants, which for convenience will be called the north, south, east and west quadrants, corresponding to the direction they lie from the station.

In beginning the test flight the instructor arbitrarily fixes the position of the plane or trainer at the point X on the chart. Bear in mind at this point that the student pilot enclosed within the trainer must now by the use of the radio signals reaching him, locate his position with respect to the airport A and still with the use of signals received, theoretically bring the ship into such airport on the radio beam. The student, of course, does not know at the start of his test flight what position the instructor has placed him with respect to the station or the beam.

For convenience, I will assume the trainer to be equipped, on this theoretical flight with the earphones 4| only and that the signals sent by the instructor and received by the student pilot are audible only. It will be understood, however, that the visual indications may also be used, alone or in combination with the audible signals. The instructor, having arbitrarily fixed the position of the trainer at X on the chart, now adjusts the secondary 38 into inductive relation with the primary 31. This results in an N or dash-dot signal reaching the pilot through earphones which tells him immediately that he is in either the north quadrant or the south quadrant, but does not tell him whether he is headed in a direction with respect to a beam which will permit him to intersect it or whether he is flying away from it. In order to find out he decides to continue flying straight north which he does for a period of say five minutes, to the position x-| as plotted by the instructor on the chart 53, the distance between the concentric lines 54 representing a certain elapsed time at a certain speed. In taking this course the student pilot first adjusts his volume control 52a to reduce the volume to the lowest audible point possible. This enables him to detect more/quickly any decrease or increase in volume than if it were turned up loud. ()bserving this/direction of flight by the student, the instructor, seeing that the pilot is flying away from the course, decreases gradually the volume of the -N signal being sent to the pilot who, noticing this decrease in volume, immediately realizes that he is flying away from the course and also that he is in the north quadrant. He thereupon turns the trainer about and begins tofly straight south, the in structor noting the change in course on the chart. As the pilot continues to fly south by his compass, he begins to approach the on-course beam" and during his approach to the beam, the instructor gradually and in accordance with the time and speed element previously determined,

this position the secondary 38 induces the combined dash-dot and'dot-dash signals from-the primaries and 31 and he hears a continuous hum and immediately knows that he has now reached an on-course beam. He does not know as yet, however, whether he has reached the 60 east of north" beam, or the 30 north of west beam. During his approach to the "beam the instructor has slightly increased the volume of the signals, and by this the student pilot realizes that in flying due south to the beam he has also flown nearer to the station and airport.

Before making a turn after reaching the oncourse signal, however, he continues to fly south to a point just beyond the on-course "beam 88, indicated at X-2 on the chart. The instructor observes this by checking the time element and at the proper moment adjusts the secondary ll towards the primary I! to give a distinguishable and predominating A signal or dot-dash to the student pilot, thus advising him that he has flown across and slightly beyond the on-course- "beam". At this point, the student, being familiar with the direction of the two beams above mentioned, knows that by turning due west he can find out whether he has intersected the east of north beam or the 30 north of west beam, for if it is the former he will, by flying due west, quickly regain the beam and if it is the latter, he will get farther away from it.

The student thereupon turns due west and shortly he again hears the continuous on-course signal, the instructor observing the turn and controlling the signals. The student now knows which beam he is on, whereupon he turns slightly south at the point X3 and starts to fly on the beam. The instructor observes from the position of the trainer, however, that the student soon starts flying slightly to the north of the course, and, in accordance with his time check, again gradually. moves the secondary 38 towards the primary 3'! to give the N signal. It should be noted here that all this time during the flight from the point X2 on the chart, the instructor increases gradually the volume of the signals which tells the pilot that he is flying nearer to the field.

When the pilot realizes from the N signal he is receiving that he is again flying to the north of the course, he turns south again at the point X-4 and again crosses the on-course -beam? and flies on past it a short distance to the point X-5, the instructor observing this carefully and adjusting the secondary 38 to provide the proper signals to the pilot to show him his position. As soon as the pilot hears the A signal again predominating, he turns north, he having by this time quite accurately determined the compass direction on the on-course "bean ,'even without previous knowledge thereof, and as soon as he again reaches the on-course signal at X6,'

he turns directly on the beam and continues directly on this on-course or constant hum signal, which the operator continues to increase in volume, until the student pilot is theoretically directly over the station 55. At this point the operator operates the amplifier control to en-' tirely cut oif momentarily, all signals to the earphones. At this the student pilot knows that he has reached a point directly over the station. It is obvious to the student that he may immediately turn back either to the right or left and come in again on the same on-course beam" for his theoretical landing-knowing that the airport is on this beam and back about two miles from the station. In the illustration here shown,

. however, the instructor observes that the pilot continues on for a considerable distance, remaining on the on-course signal. The instructor gradually decreases the volume of the signal, thus telling the pilot that he is now flying away from the fleld. At the point X1, the student turns the trainer to the right to fly back to the field. As he does so he enters the A signal zone (the west quadrant) on the opposite side of the field from which he originally came in, which is a further check to his position, the instructor moving the secondary 38 towards the primary 36 in order to provide this A signal. The student now turns back on to the on-course beam and'retraces his path over the station 55, receiving the silent signal as he does so. ie now knows that the airport A lies about two miles directly ahead of him and that he can safely lose altitude'with confidence as to his position.

This is but one illustration of any number of maneuvers and test "flights which a student pilot undergoes in his training and instruction to fly by radio. During this or any of such test flights" the student, of course, periodically hears the station call in the manner previously described, this being taken care of automatically without the necessity of the operator controlling it. Thus the student is taught not only how to fly directly on a radio beam to' a given station and airport but is taught how to locate his position with respect to such station and beam, if lost, and to get on to such beam with a minimum loss of time.

After but a very few hours instructions and practice in a practical application of this invention, a pilot is able to take a real aeroplane into the use of his receiving set and they actual broadcast of the radio signals from the station and airport, to easily and readily fly by radio.

Once again the'importance and value of training of this kind is emphasized because of the saving of expense of actual flight, which, if blind flying conditions are followed by hooding the pilot in the plane, requires an additional pilot in the open for safety, and eliminates the hazard of actual blind flying practice.

It will be apparent that many changes may be made by way of detail without departing from the spirit and scope of my invention. I do not limit myself, therefore, to the exact form herein shown and described, other than by the appended claims.

I claim:

1. An apparatus for instruction and training in flying by radio comprising a grounded trainer controllable as to direction, means observable from a position away from said trainer for indicating the compass position of said trainer, means in said trainer for receiving signals simulating radio signals broadcast to aeroplanes in actual flight, means for creating and transmitting such signals ,to said receiving means in accordance with the observed compass position of said trainer, and means on said creating and transmitting means for varying the intensity of such signals.

2. An apparatus for instruction and training in flying by radio comprising a grounded trainer controllable as to direction, means observable from a position away from said trainer for indicating the compass position of said trainer, means in said trainer for receiving signals simulating radio signals broadcast to aeroplanes in actual flight, means for creating and transmitting such signals to said receiving means in accordance with the observed compass position of said trainer, means on said creating and transmitting in accordance with the observed compass position of said trainer, and means on said creating and transmitting means for varying the intensity of such signals. r

4. An apparatus for instruction and training in flying by radio comprising a grounded trainer controllable as to direction, means observable from a position away from said trainer for indicating the compass position of said trainer, means in said trainer for receiving signals simulating signals broadcast to aeroplanes in actual flight, means for electrically creating and transmitting such signals to said receiving means in accordance with the observed, compass position or said mm a. LINK, Jn. 

